WHAT IS HPV?
Human papillomavirus (HPV) is a common virus that affects both men and women. These infections are often transmitted sexually or through other skin-to-skin contact. 8 out of 10 people will get HPV at some point in their lifetime.
There are more than 100 subtypes of HPV. Most HPV infections clear up on their own and do not cause any problems. Persistent infection by certain HPV types can cause cancers or genital warts. Almost all cervical cancer cases (99%) are linked to genital infection with HPV. HPV can also cause other cancers such as anal cancer, oropharyngeal cancer , vaginal cancer and vulvar cancers.
The best way to prevent HPV infection is to get vaccinated. The vaccine is made from one protein from the virus, and is not infectious, meaning it cannot cause HPV infection or cancer.
HPV vaccine has a reassuring safety record that is backed by over 10 years of research. These studies show that HPV vaccine is not associated with any serious safety concerns. HPV vaccination is safe for boys and girls. The vaccine provides long-lasting protection against high-risk HPV strains for at least 10 years.
DIFFERENT TYPES OF HPV VACCINATION
|Gardasil (quadrivalent vaccine)||Gardasil 9
(9- valent vaccine)
|HPV 31, 33, 45, 52, and 58||Nil||Nil||Targeted|
|HPV 6, 11||Nil||Targeted||Targeted|
HPV types 16 and 18 cause about 70% of all cervical cancers worldwide. These 2 subtypes are targeted by all 3 HPV vaccines (Cervarix, Gardasil, Gardasil 9). HPV types 16 and 18 also cause nearly 90 percent of anal cancers and a substantial proportion of vaginal, vulvar, and oropharyngeal cancers.
HPV types 31, 33, 45, 52, and 58 cause an additional 20% of all cervical cancers worldwide. These 5 subtypes are targeted by Gardasil 9 vaccine, thus increasing the protection for cervical cancer for Gardasil 9 as compared to Gardasil and Cervarix.
HPV 6 and 11 cause 90% of anogenital warts. These 2 subtypes are targeted by the Gardasil and Gardasil 9 vaccines.
Gardasil and Gardasil 9 have been approved for use in both females and males. In Singapore, boys are licensed to have Gardasil or Gardasil 9 (not Cervarix) for protection against genital warts, premalignant disease of anal canal and anal cancer.
HPV vaccines should be administered intramuscularly in the deltoid region of the upper arm or in the higher anterolateral area of the thigh. The preferred site is the deltoid region of the upper arm.
|Recommended number of doses||Recommended dosing schedule||Target population|
|2||0, 6–12 months||Persons initiating vaccination at ages 9 through 14 years, except immunocompromised persons|
|3||0, 1–2, 6 months||Persons initiating vaccination at ages 15 through 26 years, and immunocompromised persons initiating vaccination at ages 9 through 26 years|
In a 2-dose schedule of HPV vaccine, the minimum interval is 5 months between the first and second dose
In a 3-dose schedule of HPV vaccine, the minimum intervals are 4 weeks between the first and second dose, 12 weeks between the second and third dose, and 5 months between the first and third dose
HPV vaccine may be given at the same time as other vaccines.
CONTRAINDICATIONS AND PRECAUTIONS
Anaphylactic allergy to latex is a contraindication to bivalent HPV vaccine in a prefilled syringe since the tip cap might contain natural rubber latex.
A history of immediate hypersensitivity to yeast is a contraindication for the quadrivalent and 9-valent HPV vaccines as these are produced in Saccharomyces cerevisiae (baker’s yeast).
For moderate or severe acute illness, the vaccination should be deferred until symptoms improve
A minor acute illness (e.g., diarrhea or mild upper respiratory tract infection, with or without fever) is not a reason to defer vaccination.
HPV vaccine is not recommended for use during pregnancy. Pregnant women should delay initiation of the vaccine until after the pregnancy.
If a woman becomes pregnant after initiation of the vaccination series, the remainder of the series should be delayed until after pregnancy. No intervention is indicated. The vaccine has not been causally associated with adverse pregnancy outcomes or with adverse effects on the developing fetus, but data on this is limited.
The most common adverse reactions reported during clinical trials of HPV vaccines were local reactions such as pain, redness or swelling.
Syncope (fainting) may occur after any medical procedure. Adolescents should be seated or lying down during vaccination and for 15 minutes after vaccination. This is to prevent any injuries that could occur from a fall during a syncopal event.
CERVICAL CANCER SCREENING
Cervical cancer screening should be performed regularly regardless of whether you have had the vaccine.
FOR PEOPLE WHO ARE ALREADY SEXUALLY ACTIVE AND ABOVE THE AGE OF 26
The benefits of the HPV vaccination is maximal for women when given before sexual activity is initiated. However, women who had sex can still benefit as they may not have been exposed to the high risk strains yet. Risk of recurrence of HPV related disease after treatment for cervical HPV disease is also reduced with HPV vaccination.
Since October 2018, Gardasil and Gardasil 9 have been approved by the FDA to be given to women and men from 27 to 45 years old.
Centers for Disease Control and Prevention (CDC) : https://www.cdc.gov
Written By: Dr Clara Ong
Consultant Obstetrician & Gynaecologist
MBBS (S’pore) | MMed (O&G) | MRCOG (UK) | FAMS (O&G)
Dr Ong graduated from the National University of Singapore in 2006. As part of her training, she has worked in various hospitals in Singapore; mainly in the National University Hospital.
She completed her specialist training in Obstetrics and Gynaecology, and obtained her postgraduate degrees from the Royal College of Obstetrics and Gynaecology, London in 2012 as well as the Masters of Medicine in Obstetrics and Gynaecology from the National University of Singapore in 2012.
She is a fully qualified Obstetrician and Gynaecologist with the Specialist Accreditation Board of the Ministry of Health, Singapore. She is a Fellow of the Academy of Medicine, Singapore. She is also an accredited Colposcopist with the Society for Colposcopy & Cervical Pathology of Singapore.
Contact: 9724 4395